Engineering-Solver

Is a tool for doing numerical calculations fast and easy. It includes units, thermodynamic properties and many more.

Quick start

Open this site Engineering-Solver.

Write a few statements like:

2+2
3 m to mm
3 m + 2 in to mm
force = 10 N
mass = 10 lb
acceleration = force / mass
acceleration to yard/s^2

You will notice you get instant results as you are typing your expressions.

Install and develop locally

Clone this repository and run the following command to install dependencies.

npm install

To test

npm run dev

To build

npm run build

Interface

There are two main areas, the input on the left and output on the right. A top navigation bar with 20 tabs and an example selector.

In the example selector you can find:

• Numbers
• Matrices
• Objects
• Variables
• Units
• Thermodynamic properties
• Psychrometric properties

You can work on any of the 20 tabs and your progress will be saved automatically after a few seconds of inactivity.

MathJS

Does all the calculations and unit conversions. Here are some useful topics from the docs.

• Expressions
  • Syntax
  • Algebra
• Data Types
  • Numbers
  • BigNumbers
  • Fractions
  • Complex Numbers
  • Matrices
  • Units
• Reference
  • Classes
  • Functions
  • Constants

Chemistry molar mass: MM()

To call this function use MM('H2O') and this will get an object with the data of the compound, including totalMass, number of atoms of each element, mass fraction for each element, etc. The formula can include a notation with parenthesis and dot notation for hydrates.

In:

borax = MM('Na2(B4O5(OH)4).8H2O');
borax.elements
borax.totalMass
borax.fraction
borax.fraction.Na

Out:

{"Na": 2, "B": 4, "O": 17, "H": 20}
381.37214 g / mol
{"Na": 0.12056344755545, "B": 0.11339055862864, "O": 0.71318738699686, "H": 0.052858606819051}
0.12056344755545

CoolProp

Used for calling PropsSI and HAPropsSI but the unit handling is done with MathJS, thus the functions are not exactly the same as in CoolProp.

Fluid Properties: props()

In:

# Saturated vapor enthalpy [J/kg] of R134a at 25C
props('H', 'R134a', {T:25 celsius, Q:1})

Out: 4.1233395323186804e+5 J / kg

References

• Sample Props Code
• List of Parameters (Properties)
• List of Fluids

Fluid Phase: phase()

It can be useful to know what the phase of a given state point is.

In:

# Phase of Water at 1 atmosphere and 0% Quality
phase('Water', {P:1 atm, Q:0 %})

Out: twophase

Humid Air Properties: HAprops()

In:

#Enthalpy (J per kg dry air) as a function of temperature, pressure,
#    and relative humidity at dry bulb temperature T of 25C, pressure
#    P of one atmosphere, relative humidity R of 50%
HAprops('H', {T:25 degC, P:1 atm, R:50%})

Out: 50423.45039102888 J / kg

• Humid Air: Sample Code
• Humid Air: List of Parameters (Properties)

CodeMirror

CodeMirror is used for editing the mathjs code in the browser and includes:

• Syntax Highlighting
• Autocompletion
  • Functions
  • Physical Constants
  • Prefixed Units
  • Variables in Scope
• Drag and Drop text documents
• Other key bindings
  • Find and replace Ctrl + F
  • The rest can be found in CodeMirror: Reference Manual

Plotly

Is used to do plots. Uses the main interface of plotly without many changes, but running first through mathjs simplifications.

Plot hello world example

plot([{x:1:5, y:2.^(1:5)}])

Plot functions

x = 0: pi/8: 2 pi;

plot([
  {x:x, y:sin(x), name:"sin"},
  {x:x, y:atan(x), name:"atan"}
])

Plot advanced functions

sigma = 10;
beta = 2.7;
rho = 28;

lorenz(t, u) = 
  [ 
    sigma * (u[2] - u[1]),
    u[1] * (rho - u[3]) - u[2],
    u[1] * u[2] - beta * u[3]
  ];

sol = solveODE(lorenz, [0, 100], [1, 1, 1]);

plot(
 [{
    x: flatten(sol.y[:,1]),
    y: flatten(sol.y[:,2]),
    z: flatten(sol.y[:,3]),
    type: "scatter3d",
    mode: "lines"
}])

Warnings

• All calculations are done locally
• There is no server saving your calculations
• Don't run code that you don't trust